Optimal Estimation : With an Introduction to Stochastic Control

This book presents the basic theory of the modern study of systems. It is divided into two major parts covered in eight chapters. Part 1 deals with optimal estimation problems, where the Kaiman filter theory is the central focus of the subject. Part 2 introduces optimal control theory.

improvements, it must be admitted that he had an advantage over his predecessor, in the number of intermediate publications, many of which might have been spared if Mr. H. had been well understood and fairly treated ; but their appearance has now placed the question of caustic in so many points of view as to render it readily comprehended by the attentive reader.
The present performance claims our particular notice, not only on account of its intrinsic merit, but for the novelty of a work illustrated by the graphic art, in a manner which must supersede all doubts as to its meeting the precise intentions of the author.
This will be best explained by transcribing part of the preface. u The study of surgery has been greatly facilitated by the in* troduction of engravings to illustrate morbid changes. Prepara. tions, wet or dry, however beautifully executed, are, from the time v of their completion, gradually losing their value, by loss of colour, change of figure, and even from the very delicacy of their mate? 4< On a review of the sh'eets, the name of the late Mr. Hunter very frequently meets the eye. Though this was unintentional, it was also unavoidable; nor is it easy to conceive how others who have gone over the same ground can have escaped the same repeated introduction of that Clarum et Venerabile Nomen." From the nature of the work, it will be easily conceived that, without the accompanying plates, the greater part of. it will be uninteresting, if not unintelligible. The author's object was minute accuracy, and to accomplish this he has availed himself of every means in his power. Hence it would be doing great injustice to his diligence were we to mutilate his work by giving any part of it in an imperfect form. We shall, therefore, transcribe some of the introductory chapters, giving an account only of the contents of fche rest. tical purposes, till Sir Everard Home introduced, as an almost universal remedy, the caustic, which that great master had reserved for the most desperate cases. The application of a general remedy implied an uniformity in the cause of the disease; and SirEverard's book consisted only of histories of cures, without due attention to that arrangement which formed a new epoch in the study of these complicated complaints. It ought, however, in justice to be remarked, that Sir Everard, in his later publication, appears to have lost much of his former partiality for severe and uncertain remedies. " Mr. Hunter has also given us a perfect and plain description of the gradual enlargement of the prostate gland, in many subjects at an advanced period of life. It is not easy to conceive what should have induced his relation, pupil, and successor, to consider a diseased enlargement as a natural formation?at a time when, as M. Condorcet remarks, anatomy has arrived at its acm?, ( when every thing which the eye of the observer, assisted by the micro-?cope, has been able to discover, is already ascertained'?could it be believed that a part should have been overlooked by all former anatomists in a gland so often and so minutely examined. If the high authority of his master, and, I may add, almost the only master acknowledged in the present day, was insufficient, tho .candid report of his own pupil might have convinced Sir Eyerard . rof his too hasty conclusion. Happily this error has led to no severity of practice, nor is it likely, nor even that the authority of Mr. Hunter's successor should induce its adoption in our anatomical schools. " In the description of the diseases of this gland, I have, therefore, retained Mr. Hunter's, and the established doctrine, concerning its original form and subsequent changes." The first chapter contains the history of two cases which, as Dr. Baillie remarks, are somewhat rare?Calculi in the prostate gland. The history during life (the great desideratum in Dr. Baillie's otherwise invaluable collection of morbid engravings) is added ; and the addition of the plates renders the whole as complete as such accounts can be made. The subject is continued in the succeeding chapter. In the third, we have a masterly representation of an enlarged prostate, with a portion projecting into the bladder, and in a state of ulceration. The fourth plate describes a bladder in a most wretched ulcerated state: the history subjoined i$ particularly interesting. The next is still more so, as being more minute. In this the prostate was enlarged, the bladder thickened, and the surface covered with coagula. In the history of the case, the author recommends injecting into the bladder, and gives some important directions for the manner of doing it. We pass over several others ?A account of the following history, the theory of which ie2 has MO Critical Analysis, has not, we think, been sufficiently reduced to proof, though among the maxims of Sydenham.
"The subject was about sixty*five years of age, had strictures, and fistulas in perinaeo; but the urethra was sufficiently open to allow the greater quantity of the urine to pass off" that way, a part only coming through the fistulas. He was very subject to the gout, and occasionally, during a fit, would be seized with strangury and retention of urine, which, notwithstanding the diseased state of the prostate, could always be relieved by means of a small gum catheter. His death was occasioned by an accident.
That gout sometimes induces a disordered action of the urethra and bladder, is generally admitted ; and the following cases seem to confirm it. The first was in a gentleman of most temperate and regular habits, who, till that time, never had a complaint of any kind in the urethra, or any of the urinary organs.'' Subjoined to the descriptions and representations of diseased bladders is an account and etching of some cancerous appearances about the nates, of calculi passed by the female urethra and cut from the male, with a diagram of the two largest calculi in Britain found in the human bladder.
The account of diseases of the testicles is introduced by a warm compliment to Mr. Hunter on the manner in which lie has reduced the laws of sympathy to some order; and also on the remarks of Mr. Abernethy, and the illustrative cases by Mr. Ramsden.
A chapter follows on Hydrocele, which contains some new matter, and some most important theories, confirmed by actual dissection of subjects whose hi|tory was known during life. As Mr. Wadd informs us, in his dedication to Sir James Earle, that he was for ten years his apprentice and pupil, and as, during that period, the mode;, of cure by injection was first introduced, this passage cannot fail to interest all our readers: we have, therefore, transcribed as much as our limits will permit. , " Whilst (says our author) I had the honour of visiting with J5j,r James Earle, there was scarcely an operation of any kind performed by him at which I was not present; and, as to Sir James xye o^we the fortunate revival of this important operation, with its fsent improvement, it will be supposed that the cure of the frocele by injecting the tunica vaginalis testis, made a very siderable part of bis practice, and gave me an opportunity of (seeing it under every form. In some cases, after caustic, seton, iricision, externa) applications, and other operations, have failed, afid even where the injection had been previously tried by others acquainted with the practice, he was fortunate enough to tflficeed. #*?]& ?nly instances of failure were two cases, ia which an at-teiaj^ * Mr.Wadd on Diseased Testicle and Bladder. 221 tempt was made at a further improvement in the operation; and a third wherein no irritation was produced, in consequence, as it was supposed at the time, of the servant's having diluted the wine. Each of these were cured by a second operation shortly afterwards. Whether even this was necessary cannot now be ascertained, but is by no means certain. " ' The proper object,' says Sir James Earle, ( of all operations for the radical cure of the hydrocele, is to produce such an adhesion of the distended vaginal coat of the testis with the^gland, or such a consolidation of contiguous parts, as shall annihilate the cavity in which the water constituting this disease is contained.' The same is Mr. Pott's language. ' The cure is accomplished merely by the coalescence of the tunica vaginalis with the tunica albuginea;' and Mr. Sharp, in his Critical Enquiry, tells us, that, 4 upon examination of several hydroceles after cure, it appeared evidently it was wrought by an universal adhesion of the testicle to the tunica vaginalis.' Such, I believe, were the sentiments of every surgeon of eminence, till Mr. Ramsden ventured to dissent from the established doctrine, asserting that the obliteration of th$ cavity of the tunica vaginalis testis was not essential to the cure, and that it did not happen unless the curative process had been carried to unnecessary severity.
i( Among my notes is a memorandum which very much confirms. Mr. Ramsden's opinions. A gentleman underwent the operation in May, 1799* He left town at the end of June. The beginning of July he stated by letter, that the hydrocele had returned as large as before the operation ; and in the middle of the next month he wrote word that it had entirely disappeared. The operation had, therefore, excited a new action in the parts, and though the effusion of fluid had returned, yet the absorbents had recovered their function. " That adhesion takes place between the tunica vaginalis and testis, where there has been a certain degree of inflammation, has been repeatedly demonstrated ; and that it is the general effect of the usual mode of injection ; but, if the cure can be accomplished by less irritation, and without any change in the parts from their original formation, many might be inclined to undergo it, who would not be willing to hazard an operation under any other circumstances.
Mr. Ramsden has not confirmed his theory by dissection, but brings abundant proof of transparency in the scrotum after the operation; and on that fact its validity chiefly rests, lie attached, great importance to the ascertaining the transparency of hydrocele, and in all cases made it his first object of enquiry, thinking that the surgeon who neglected this 'grand characteristic' gratified his vanity at the risk of his patient's security.
The usual injection is two parts wine to one of water, or if the tunics are thin, the testicle enlarged, or any circumstance require caution, it is made of equal parts, wine and water. Even thf ?50 Critical Analysis. the Tatter proportion is sometimes productive of considerable pais aod tumefaction. " With a view of following Mr. Ramsden's plan of curing by cnly exciting a new action, with as little pain as possible, I hare so lessened the quantity of wine, that the irritation produced has been such as not to detain the patient at home after the day on which it was nsed ; and I am inclined to think that very little irritation of the sacculus is sufficient for the cure of most hydroceles, that do not exceed half a pint in the quantity of fluid, nor six months from their first appearance.*' This subject is enriched with many accurate etchings, which, though they possess not all the softness of engraving, are sufficient for every purpose of illustration. On the ?whole, we are so well pleased with Mr. Wadd's performance, that we are anxious to see his example followed, and ex-? Art. V.-?Case of Fracture of the Skull, in which, a quantity of Brain was lost, and a real Hernia Cerebri successfully treated by Pressure; and an Account of the good Effects of Tincture of Bay-leaves to Wounds, Ulcers, Bur?ist $?c. and of Charcoal internally in Dysentery. By C. I?. Crawford, Surgeon, R. N.
The title of this article speaks for itself. The subject of the hernia cerebri was a boy betwixt two and three years old. No part of the scalp was lost.
Art. VI.?Case of very extensive Wound of the Abdomenxwith complete Division of the Ileum, and Penetration of the Cavity of the Thorax. By Thomas Calton, Surgeon, Collingham, The subject was a boy seven years old, and of a peculiarly placid temper. We mean not by this to undervalue the t;ure; but, as far as we conceive our duty, to add to its credibility.
Art. VII,?On Puerperal Fever, as it appeared at Holloway, near London, in the early part of the year 1812. By David Dunn, Member of the Royal College of Surgeons in London.
"We shall spare Mr. Dunn and his friend Dr. F., whoever he is, by passing over the two first cases. It is, however, creditable to the author, that he improved by an examination, tf the dead bodies. But that a practitioner so near town 1 should Edinburgh Medical and Surgical Journal. 2<2J should never have known the necessity of bokl blood-letting in puerperal fever, (which maybe called peritonitis,) before these cases occurred to him, nor have read nor heard of it till Dr. Armstrong and Mr. Hey wrote, surprises us a little.
Art. VIII.?Three Cases of Inflammation of the Heart, with the appearances on Dissection. By Andrew Duncan, Jun. M.D. Professor of Medical Jurisprudence in the University of Edinburgh.
The first of these cases occurred in a miner, twenty-eight years of age. We shall give the symptoms and appearances after death in the author's own words, omitting the treatment, which is the less important as it was unsuccessful.
" Complains of severe head-ach, and a gnawing pain in the region of the stomach, not increased by pressure, but much aggra* vated on taking food ; with a sense of a ball in the under part of the abdomen, working upwards through the course of the alimentary canal to his throat, when he feels as if immediate suffocation would ensue. This feeling he has experienced almost every night for nearly three months past. Frequently, although not always, at the beginning of each paroxysm, he has a very copious flow of urine, approaching nearly to the colour of table-beer..
During the fit his belly swells, and it is always relieved by a great discharge of flatus by the mouth. He is not sensible of foaming at the mouth during the paroxysm ; nor, if standing, is he thrown to the ground, but becomes so giddy as not to be able to stand without assistance.
He also complains of great debility, want of appetite, interrupted sleep, and a disagreeable taste in his mouth on awakening in the morning. Has a delicate look; pulse 104, of moderate strength ; heat natural; tongue covered with a brownish crust, with a clean edge; some thirst; belly costive, in which state he always feels worst; urine varies; when his complaints are severe, it is increased in quantity, and of a higher colour.
14 Began to complain about three months ago. Was first seized with the pain and sense of tightness in the region of the stomach. Can remember no cause for his complaints, except being exposed to cold and hard work. Nothing happened at that time particularly to affect his mind. Says he has used stomachic bitters and bark, without alleviation of complaints. Was formerly troubled with symptoms nearly similar to the above, but never to such a height. Was able always to follow his occupation, and enjoyed a good appetite." " Sectio Cadaveris.?The contents of the cranium, thorax, and abdomen, were carefully examined. 225 4Tie abdomen, which, except where it had touched the gall-bladder* and in eonsequence acquired the colour of bile, was of the usual yellowish tint, and quite transparent/' A long series of reflections,by the author follows: some of these we shall notice.
u This case appears interesting, (( 1st, From its rapid and unforeseen event. " 2d, From the appearances discovered on dissection. <( When admitted, it was supposed to be a case of hysteria in a male,?a rare occurrence, yet not unobserved. Some consider hysteria and hypochondriasis as the same state of disease, modified by sex; the former being peculiar to women, the latter to mei*. This is, in general, true, but exceptions do occur ; and it is not fuffieient to reject all the testimonies adduced in proof of this, because we ourselves have not seen it.
Unequivocal cases of hysteria in men have been seen by Dr. Trotter and others. Hypochondriasis certainly oftener affects females. " The difference between them depends much on temperament.
Hysteria is peculiar to the sanguine, and hypochondriasis to the melancholic, temperament. In hysteria, the affections of the mind are characterised by fickleness and mobility ; in hypochondriasis, by the obstinacy with which the mind broods over a single subject. In hysteria, the patient is violently affected by every circumstance external to herself, and is agitated by every sudden impression ; but the paroxysm is* no sooner over, than she laughs at her own Folly, thinks no more of it> and resumes her wonted spirits. Ia hypochondriasis, on the contrary, external circumstances make little-impression on the patient; and if a sudden and-violent impression rouse him for a moment, he speedily returns to brood over his loss of health, or finds in what has just passed fresh cause for despondency.
" The symptom1 in Baxter giving rise to the idea that his disease was hysteri^ was the accurate description he gave of the globus hystericus. But after he came under our care, the symptom did not recur. " I was then> led to consider his complaint as hypochondriasis, from the pain of stomach, increased on taking food; the irregular atate of his urine ; the costive belly ; flatulence; interrupted-sleep:; bad appetite; foul tongue, and bad taste in his mouth; and still more by his constant complaints* I therefore left him a day or two to. observe the symptoms." We would only remark, that hypochondriasis is a very g^neraly and, unfortunately, a very ill-defined word. In .common language, the man had all the symptoms of hypochondriasis;, but we regret exceedingly that a professor should be so led away by a nosological term, as to leave so interesting a case for a day. or two. We wish we had a closer .description of* this " efflorescence, not unlike that which is no. ?05. f f ' often 426 Critical Analysis, often exhibited by hydatid cysts." Were they cjrsts, of what was the difference ? No one will question that there was disease enough to kill a man, or that the whole was formed before the author of the paper had any interview with the patient; but it would be very desirable to know whether these appearances were the effect of violent inflammation at a remote period, or had gradually grown during the last complaints. We are well aware of Corvisart's distinctions between the acute, sub-acute, and chronic inflamma-* tion of the heart; the great objection to which is, that the two latter are, we fear, often the consequence only of the first, which was violent enough to produce effects that must prevent the future regular functions of the heart, but not sufficient to produce immediate death. This is a question of the ?utmost importance, inasmuch as its decision would lead to a due consideration of arresting, at all events, and in its earliest stage, high inflammation in vital parts, without waiting to determine whether we have carditis, pericarditis, or diaphragmitis, or whatever other itis we may meet with in nosological tables or dictionary writers.
Dr. Duncan produces some very judicious references to Morgagni and others, concerning diseases in the cardiac system. The only one to his purpose is the case of the Venetian woman, which makes the 23d article of the 44th epistle. This case is highly important on another account, which is only slightly hinted at in this place, but which we shall notice the first time a question occurs concerning the uncertainty of the signs of life. " She was dissected (says Dr. D.) ten hours after death, and Morgagni, having doubts that it had actually taken place, proceeded with the utmost caution,, after having made all the usual experiments to ascertain it." The doubt which embarrassed Morgagni and his friend arose from the body remaining warm ; a question which we are astonished has never occurred to the writers on medical jurisprudence, and which we are still more astonished has never been attended to by the various experimenters and inquirers into the causes of animal heat. But of this more when a proper opportunity offers. Some judicious remarks follow on the texture of muscles, and the changes they undergo with a view to form a similar analogy regarding the muscular part of the heart. We roust not, however, pass over one instance of scepticism concerning a question highly important in this and all other inquiries concerning the heart. 44 It is not yet ascertained (says our author) upon what the red colout Edinburgh Medical and Surgical Journal. 287 colour of the flesh of man, and the higher orders of animals, de-pends. For the fact, that red muscles become white by washing, does not prove that the red colour depends upon the blood, but only that the colouring matter is soluble in water. Fishes have red blood, and yet many of them have white muscles; and, in some animals, different muscles differ very much in colour. This is especially remarkable in the black cock, where the outer layer of pectoral muscles has a very dark colour, and the inner is white, so that, in cutting out a slice of the breast, we have flesh of two very different colours, and yet supplied with the same blood, and even from the same arterial trunks.'' In answer to this, we shall only say, in the words of Mrf Hunter, that in all quadrupeds most of the muscles are red. That this redness arises from the blood, is proved by the muscles being red in proportion to the quantity of blood they contain, which is in proportion to the quantity of use required of them. This is evident in all the muscles with whose actions we are acquainted, and is particularly striking in the heart, whose action, being constant, requires the most blood, and in all red-blooded animals it is found the reddest part: next to this are the sphincter muscles, whose actions are also constant, though not to so great a degree. It is not less certain that muscles lose the redness they have acquired in proportion as they are less used. This is an important consideration in the heart, as we shall presently see.

22S
, Critical Analysis, texture. In short, the change of texture may be best described, by saying, that, in a considerable portion of this heart its grain bad become much finer than natural; so line, indeed, that, without the assistance of art, the fasciculi upon which the grain of muscles depends could not be recognized. " This change was dispersed through different parts of the heart, but was chiefly obvious in the right auricle, septum, and left ventricle. In general, the change was less perfect near the inner surface, so that there the flesh, though white, was still visibly fibrous; while, as it approached the outer surface, its fibrous arrangement disappeared altogether. Yet, in the midst of these cartilaginous-like portions, a small bundle of red fibres was occasionally intermixed.
i(-As it is highly improbable that an alteration of structure of this hind took place in the course of the few days during which Baxter declined so rapidly, we may suppose that it is not inconsistent with the heart carrying on its functions with tolerable regularity. 4t To ascertain this point, however, we should compare the phenomena which have occurred in other cases of the same kind, -??but here we altogether fail; for, so far as I have been able to discover, no case exactly resembling this, in the kind of alteration of substance, has been observed, unless, perhaps, that which I have translated from Morgagni.
" It is not unusual to observe white opaque spots upon the surface of the heart, sometimes thicker, and sometimes thinner; sometimes more, sometimes less distinct; and, at first sight, this heart seemed to present a spot of this kind, larger, thicker, and more distinct than usual; but, on cutting into it, the difference ?was obvious, for these spots are owing to the formation of a false membrane exterior to the proper co^t of the heart, so that it can be removed, and leave the heart covered with its proper tunics.
This appearance occurs so often, that Baillie and Soemmering do not consider it as being morbid. In Baxter's heart, however, it appeared that the white spots were owing to the substance of th? beart itself being altered in composition." u The next morbid appearance (proceeds our ingenious author) noticed in Baxter's, was a sort of efflorescence, covering the inner surface of the right auricle, not unlike that which is often exhibited by hydatid cysts. It consisted of globular and pedunculated masses, attached to the parietcs, and had very much the appearance of fatty particles; but on analyzing them by fire, they were evidently fibriue or albumen, at least when placed on hot iron they did not melt, but shrivelled and burnt with the smell of feathers.
"The question in regard to these is, whether they existed during the life of the patient, or were first formed by the gradual coagulation of the blood after death, and the concretion of its coagulable Jymph with the sides of the auricle. But, besides occurring in the aujicle, it appeared that a similar substaacc, but more in the fyra Edinburgh Medical and Surgical Journal. 229 form of a membrane, had lined the right ventricle, at least fragments of it, passing under the columnae carneae, still remain in the prepared heart. " Except in general form, these have a considerable resemblance to the polypi of the heart, about which it was so long, and is still, disputed, whether they were formed before or after death ; and probably the same arguments may apply here, as the only difference is, that, in the usaal form of polypi, there are one or more long fibrous-like masses of considerable size, often entering into the mouths of the vessels. That the great majority of these are formed after death, there cannot be a doubt; indeed there are few bodies in which they are altogether wanting; but still there seem to be incontrovertible proofs of their being occasionally formed during life. The most decisive instance of this that I have met With, has been admirably described in this Journal, by my friend, Mr. W. Wood. Indeed, I am inclined to think that the loose body, as well as the attached mass, observed by him, had the same origin with what Dr. Gordon and myself have denominated the efflorescence in Baxter's heart. At any rate, they prove the possibility of its having existed there long before death, which becomes mofe probable when we consider, that such an appearance would be often observed, if it originated in the coagulation and separation of the blood in the heart after death, as in this there can be no great diversity. The great objection to this opinion is the natural state of the circulation during life ; but this admits of explanation, as no part of this efflorescence was loose, or situated so as to obstruct the flow of the blood. " There are three ways in which such concretions may be formed: 1. By an organized growth from a surface of greater or less extent. 2. By an inflammatory exudation from a living surface, such as takes place often on the lungs, and sometimes on the outer surface of the heart itself. And, 3. The coagulation of blood, in consequence of a portion of it being removed out of the current of the circulation, and becoming stagnant. " In the first manner are formed tumours, warts, &c.; and sometimes even loose bodies, by their subsequent separation, when originally attached by a narrow neck; but this could not be the process in the present instance." On this subject we have, of late, so amply delivered our opinion, in our remarks on Mr. Hodgson's very ingenious and well-conducted inquiries concerning the diseases of arteries, that we shall only refer our reader to them Indeed we hardly know how to account for Dr. Duncan's passing over Mr. Hodgson's labours in this part of his reflections.
All further remarks we shall preserve for the conclusion of the article.
Of the second case we shall transcribe the passages most important to pathology j the death of the patient in this, as and of difficulty of breathing, aggravated by exertion. She is un.
able to lie in the horizontal position. 44 Complains also of pain in the right haunch, increased by pres* sure and exercise, but unattended by swelling. There is also con* siderable swelling of both ankles, which pits slightly on pressure ; but there is no discolouration of the skin, nor is there any pain. Pulse 88; H. moderate; tongue rather white; much thirst; appetite bad; B. costive; catamenia irregular; urine natural; sleeps ill.
4 'Complaints first began about ten days ago, with shivering and flushing; pain in the breast and cough, followed the next day by pain in the shoulders, elbows, knees, and right haunch ; but the pain in all these joints, with the exception of the last, is now gone.
*' Has been bled, and taken purgatives and diaphoretics, but with little benefit. 44 Attributes her complaints to exposure to cold. 44 Mitt, sanguis ad ? xij. pleno rivo. 44 App. vesicat. parti affect. 44 12th.?Was bled last night; no buffy coat on the blood, which, however, is tolerably firm. The blister applied to her side rose very well; but, as she was not relieved this morning, she was ordered to be bled again, but would not submit to the operation. Has a very severe cough, which distresses her much; and she has had no sleep for eight nights past. Has had no stool. The paia in the side, where the blister was applied, is relieved, but it is more severe in her breast. Pulse 88, rather full, and somewhat hard.*' This plan was continued or altered, as circumstances required, till the 13th of the following month, when the patient c(ied ; and the examination of the body will readily account for the Avant of success, however judicious the treatment might be. 44 Sectio Cadaverts.?On laying open the thorax, a considerable quantity of fluid was found effused into the cavities of the pleura, on both sides. 41 The lungs on both sides seemed quite healthy, and of their natural colour; but, on endeavouring to raise them up, they were found to adhere firmly to the pericardium, through its whole extent ; to the diaphragm; and laterally to the pleura costalis, by membranous bands; and the lobes were firmly attached to each other, so that they could not be separated without some difficulty.
The pericardium was found adhering so firmly all round the heart; Edinburgh Medical and Surgical Journal. 231 heart, that it was with difficulty raised from it. It was very much thickened, and evidently consisted of three laminae; the middle one being opaque, white, and dense; the outer very unequal in thickness; and the inner very vascular, red, and pulpy. " The heart itself was a good deal larger than natural, and was also thickly covered with coagulable lymph, which, owing to its being torn asunder from the pericardium, appeared very irregular on its surface. Under this lymph, about two-thirds of the thickness of the heart had been changed into a substance somewhat re, ?embiing in its appearance condensed fat; and was found in fact to contain fat, as it swam in water, melted, and stained paper with a greasy stain : the remaining third had almost lost its muscular appearance.
" The columnae carneae in both of the ventricles were larger than natural. Ossification had just commenced in the semilunar valves, at the mouth of the aorta; but the mitral valve was thickly beset ?with osseous matter." Among the reflections of the author, we shall only select the following paragraph. not a very rare occurrence. I have myself seen it in a man wfia> died apparently of asthma, and Corvisart has a chapter on the subject. But the most remarkable circumstance in this woman's heart was its partial conversion into fatty matter. Of that I was assured) not only by its appearance, but by chemical experiments, which were perfectly conclusive as to the fact. Corvisart himself never saw an example of this conversion, but says, that it has been seen by some modern anatomists, although their observations have not been published. He also confesses his ignorance of the manner in which such a transformation takes place. In the present instance, we find it accompanying pericarditis, but it does not follow that it was an effect of the inflammation. It may have existed before the commencement of the fatal disease.
I dp not know that any connection has ever been traced between the conversion into fat of other muscles, and preceding inflammation. 44 The commencing ossification of the valves, in so young a woman, is, however, an argument in favour of some state of inflammation having existed in the heart on a former occasion ; and the membranous bands, causing lateral adhesions of the lungs, were evidently the effect of pectoral inflammation some time before the fotal attack." We come now to the third case contained in this interesting and important paper.
" John Macleod, set. 17, sailor. u January 25th.?Is affected with pain in the right side, on deep inspiration or on cough; which last is pretty severe, and attended by a very bloody sputum. The chest feels hot but not oppressed. Has head-ach, nausea, retching, and an occasional vomiting of a slimy black matter. Thirst; tongue whitish and moist at the edges. !No appetite; B. regular; no sleep; pulse 92, smalt and soft. " Complaints of three days duration. Sputum became bloody yesterday morning. Was immediately bled to considerable extent;* and a cathartic was administered." The patient lived, under various treatment, for sixteen days.
" On opening the thorax next day, few or no adhesions were observable; nor was there any considerable effusion of serum into the sacs of the pleura. A little to the right of the sternum there extended from the lower part of the left side a dirty chocolatecoloured bag, which, on being opened, proved to be the pericardium adhering to the lungs, thickened and much distended'; also containing two pounds six ounces of perfectly formed pus. " The inner side of the pericardium, and that part which i? reflected over the heart, were covered with a thick coating of a substance resembling condensed curds : and in some parts to a greater depth than others. " The substance of the heart was very much paler than Hsual.
It had no other peculiarity. the heart itself, as its outer membrane, aud where it is reflected as a loose bag around it, there was almost no affection of the neighbouring parts. M The leading symptoms were at first pain in the right side; certainly a very anomalous symptom, but it must be observed, that the pericardium extended to the right of the sternum ; cough, with bloody expectoration; head-ach; nausea; retching; and occasional vomiting; pulse 92, small and soft. In the progress of the disease, the pain became general over the left and lower parts of the heart; the retching continued ; the pulse became quick, feeble, and intermitting; and delirium came on. The bloody expectoration was for a short time suspended, and then increased so as to amount to hemoptysis. At first he complained of want of sleep, afterwards he slept or dosed a great deal. His cough and dyspnoea fluctuated, but increased towards the close of his life, which took place on the fifteenth day from the attack. " These cases seem to ine to form a valuable addition to our knowledge of this interesting disease. In Baxter we have an example of chronic and occult carditis, without any.symptom occurring to indicate the affection of the heart; while after death the effusion of coagulable lymph, both into its cavities and into the pericardium, and the change its substance had undergone, left uo doubt as to this important organ having been generally affected with inflammation. In Rickman and Macleod, we have cases of acute or subacute pericarditis; the former, accompanied by effusion of coagulable lymph, would have produced, if the patient had survived, a general adhesion of the pericardium, aud the latter terminating in an enormous, and necessarily fatal, effusion of pus. The symptoms during life were no less different than the appearances after death; but any attempt to connect the one with the other would be premature." The few remarks we shall offer will be less necessary for those who have perused with attention our analysis of Mr. Hodgson's performance. We shall, therefore, only repeat, that all the appearances described in these cases prove high inflammation in the early stage of the diseases, at which time only they might probably have been all relieved. It was unfortunate for all these patients that they were seen so late in the disease by the judicious author of the paper ; otherwise, it is at least probable, that all the calamitous events which followed might have been prevented, and, to render the paper practically useful, this, we conceive, should have been the object constantly kept in view in every part no. 205, G g of 234 Critical Analysis, of the detail. That the symptoms were those of debility in the end is evident by the wine directed in one instance, and the wine-whey in the other. But whence, it should be enforced on every young practitioner, did this debility arise, and what would have been the means of preventing it? The answer is ready. By checking the inflammation in the first instance, and thus preventing the irrecoverable condition of so important an organ.
The only additional remarks we shall make on the various appearances are:?that flocculi on the inner surface of the heart or larger arteries rarely appear unless the internal surface has been destroyed by previous inflammation ; that there is reason to believe coagula on the sides of these parts when smooth, particularly if uniting an organ and its investing capsule, will, if the patient survives, gradually elongate so as to give an increased scope towards the original motion of these parts on each other; that the pieces of coagulum found, whether in the heart or arteries, arise from the high disposition which is found in the blood to coagulate in the living body, when parts in the neighbourhood are highly inflamed. Such is the true theory of Mr. Hunter's adhesive inflammation. The opinion that such coagula are formed by the stagnation or slow motion of the blood within the heart or arteries, is erroneous, because such a cause in the living body is not equal to such an effect as Mr. Hunter has proved experimentally in several trials. The opake spots on the heart are frequently seen, and when we know the history of the patient may be always accounted for by some previous inflammation.?See Sir Everard Home's Account of the Examination of Mr. Hunters Body. The fatty appearance or change of the muscle to adipocere can only be explained at present in one way. Inflammation may be carried to the point of mortification. As we rarely find suppuration from mere inflammation in muscles, and never we believe hitherto in the heart, the mortified portion must remain without being separated \ and in this state, having lost all the properties of life, it becomes in the condition of those muscular substances which have been for some time kept from the air in moist siCuations: that is, it is Convertible into adipocere.
Whilst we have made these very free remarks on Professor Duncan's paper (all of them, we assure him, confirmed by the examination of cases under our own inspection,) we are free to acknowledge the obligations we owe him ; and earnestly recommend him to pursue such inquiries in private families, where he can with more certainty learn all the previous symptoms.
Art. A work on the Diseases of Children, from a practitioner of Dr. Clarke's age, experience, and celebrity, cannot be }>erused without interest. After filing, if we may be aU owed the expression, all his practical observations, by several years' public lecturing and frequent consultations, we might expect a concentrated series of aphorisms, which the young practitioner should always keep in view. If we are disappointed in this respect, it is, probably, because this meritorious physician has not lived to complete his labours.
We must, therefore, be thankful for the volume as it is; and only hope that his surviving relation will, from the notes of the deceased, and his own observations, favour the world with that accumulated knowledge we have a right to expect from such sources. This is the more to be desired, because the Preface informs us that in a future part it is the author's intention to enter more at large on medicines proper for children-?'* to lay before the reader some account of those medicines which, in the course of long experience, have been found to be most useful in the various disorders of children." Registered. This is evident by the language of those documents, which only mention burials, and in what parish-* churches, or parish burial-grounds.
From the bills, however, imperfect as the are, the author draws the following conclusions, taking the gross numbers for the last forty years of the preceding century. <c It appears from this table of the burials, as published id the bills of mortality annually, that in forty years the whole number of burials amounts to 836,285. 44 It appears that of this number 2SJ,408 died before they had attained the age of two years ; and that, of the surviving 554,877 (after deducting*those who died under two years of age), 113,393 died-before they reached the age of ten years.
" If the assumption above stated be true, that In early life the? births and burials are equal, then it follows, that of all the children born within the district comprehended in the bills of mortality, nearly a fourth die under two years of age; and of the survivors, about a fifth in the succeeding eight years, that is, under ten years* of age.